The present invention relates generally to a timer for containers or dispensers, which displays the time that has elapsed since the container was last opened, and in particular to a timer that can be affixed to the lid of a conventional container for prescription medicine.
Errors related to the administration of medication are well documented in pharmacy and medical literature. Many administration errors are due to inappropriate time intervals between doses. The result can be either overdosing leading to toxicity, or under-dosing causing a sub-therapeutic drug blood level. There are solutions to this dosage interval problem in prior art, but problems permeate these prior solutions. These problems may be divided into five general areas.
First, there are the timing devices that require repackaging the medication, that is, removing the medication from the container originally provided by the pharmacy or manufacturer. These devices may result in errors during repackaging, loss of original labeling, and loss of physical and chemical protection provided by the original dispenser.
Second, some timing devices replace the original lid, while retaining the original bottle or vial that was provided with the medicine dispenser. This again may alter the physical and chemical properties of the original packaging. Replacement of the original lid also necessitates that the timing device be manufactured in a vast array of configurations and sizes to fit the large variety of containers currently in the marketplace.
Third, medicines provided as a liquid present problems, as the closures for bottles are different than those found on containers of solid dosage forms, such as vials. For example, the closures for bottles are typically screw-on caps, which create an air-tight seal. Many of the prior art timing devices cannot be readily adapted to bottle caps.
Fourth, many timing devices and systems require programming or record keeping. Programming can be difficult for patients who are disabled or elderly. Multiple medications can complicate programming requirements and multiple caregivers can add to problems with devices that are difficult to use.
Fifth, various original container lids require a particular pressure and/or motion to open and close the container. Not all add-on devices are compatible with the range of lid types offered. Further, some prior art timers are equipped with manual reset features or procedures in an attempt to expand their utility. But, if the timer is not automatically actuated by the act of accessing the contents of the container, and the patient is required to manually reset the timer, then the reliability of the timer can be compromised.
Examples of timers for medication dispensers are shown in the following references. U.S. Pat. No. 4,419,016 discloses a timing device for indicating when the medication was last accessed, which includes a container with a screw on cap. The cap contains a compression switch to indicate the time when the container was last opened to remove a dosage of medication or to display the time elapsed since the cap was last taken off of the container. The cap is said to fit standard vials or container. Variations of a compression switch are disclosed, such as a pliable extension which is inserted between the cap threads and the bottle neck threads so that as the cap is threaded on the neck, the pliable extension is compressed and contacts within the extension are actuated.
U.S. Pat. No. 4,939,705 discloses a container and cap combination, wherein a timing device in the cap measures a time interval between when the cap is removed and when the cap in reinstalled to determine a true medical dose access event and distinguish them from false events. Additionally, the timing device may include a memory for storing events, and the memory can be accessed and reviewed. The disclosed dispensing container would require redistribution of medicine from the original containers presently used by pharmacies.
U.S. Pat. No. 5,233,571 discloses a replacement cap for medicine dispensers. The original lid is replaced by a cap containing a timer/alarm, which is activated by a compression switch. Since the cap is intended to substitute for the original lid, the cap is provided with internal threads or other means to engage the container. Consequently, the replacement cap must be matched to fit a particular, original container for medicine.
U.S. Pat. No. 5,751,660 discloses a timing device having a specially designed container (vial) and a base for supporting the vial. The base includes a push button that needs to be actuated by a patient, to set the time at which the medication was taken.
U.S. Pat. No. 6,845,064 describes an add-on medicine dispenser timer, which can be affixed to a conventional medicine dispenser lid. The add-on timer has a housing, with resilient side walls. The side walls flex when downward pressure is applied to the housing and a compression switch is actuated, which resets the timer. Visual inspection of the display indicates proper reset of the device.
The objectives of the present invention are therefore to provide a device for the timely administration of medication that does not require the repackaging of medications from the original container and that does not require replacement of the original container lid. The timing device should be compatible with and readily actuate when used on all types of child safety and other closures commonly found on both solid and liquid dosage forms of both prescription and over-the-counter medications. Additionally, the timing device should be simple to use and not require programming or initial set-up, other than the affixation to an existing container lid. Once the add-on timer is properly affixed to an existing container lid, accessing the contents of the container should actuate the device. The affixed timing device should not significantly alter the pressure or motion required to access the container. Further objectives are to provide a device that is compact, inexpensive to manufacture, and reliable.